Olympus 28mm f2 lens and adapter question

I bought a used Kiron 28mm f2 lens from Ebay, and an Olympus-to-nex adapter. The aperture ring on the lens doesn't do anything (stuck wide open). Do I have a bad lens, or is there some interaction with the adapter/mount?

I tightened the lens on the adapter, but I don't get a satisfying "click", and if I try harder it tightens more. I worry about stressing the lens. Anyway, I tightened it enough for the tab on the side of the adapter engages a pin on the lens. There's another pin on the other side that isn't engaged by the adapter. Does this sound right?